How to make it:
Start with combining flour, eggs and a good-sized pinch of salt. Blend well and add water if necessary, spoon by spoon. The dough should not be runny, but soft enough to gradually follow gravitation. Then set aside and allow the dough to rest for 20 to 30 minutes.
Meanwhile heat the butter in a frying pan over low to medium heat, add onions, and let them slowly gain a golden brown colour. Don't let them get too dark, as they tend to become bitter. Drain on a paper towel and then set aside.
Bring a large pot of water briefly to a boil, add a pinch of salt and then reduce heat. The water should simmer throughout the whole process. You can either cut and shape the spaetzle by hand or use a spaetzle maker or a colander which makes things easier. Cook the spaetzle for about 2-3 minutes until they float back to the surface, then remove them.
When done, drain the water, melt 1-2 tbsp of butter and return the spaetzle to the pot. Shake the pot a few times to evenly distribute the butter, then add the grated cheese and mix well.
Now simply add the browned onions and chopped chives on top and serve.